Variable friction-drive.



A. E. HILL;

VARIABLE FRICTION DRIVE.

APPLICATION FILED DEC.26, 1914.

Patented Jan. 11, 1916.

2 SHEETSSHEET I- THE COLUMBIA PLANOGRAPH c0-, WASHINGTON. D. c

A. E. HiLL. VARRABLE FRICTION DRIVE.

APPLlCATlON FILED DEC- 26, 1914.

Patented Jan. 11, 1916.

THE COLUMBIA PLANOCIRAPH .CO., WASHINGTON. D. c.

ALBERT E. HILL, OF ATLANTA, GEORGIA.

VARIABLE FRICTION-DRIVE.

Application filed December 26, 1914.

To all whom it may concern Be it known that I, ALBERTE. HILL, a citizenof the United States, residing at Atlanta, in the county of Fulton andState of Georgia, have invented certain new and useful Improvements inVariable Friction- Drives; and I do hereby declare the following to be afull, clear, and eXact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to machine 'elements, and more especially tofrictional driving mechanisms; and one object of the same is to producea mechanism of this kind, especially adapted to grinding machines, andin which the friction idler has a changeable contact with the drivervaried by the load thrown onto the driven element.

' Another object of the invention is to provide a machine of this naturewhere the feed of the driving power will be automatic to the extent offurnishing additional power to rotate the honing table when increasedpressure is brought to bear upon the table.

With these and other objects in view, the invention consists in certainnovel constructions, combinations and arrangements of the parts as willbe hereinafter fully described and claimed.

In the accompanying drawings wherein similar reference charactersdesignate corresponding parts: Figure l is a perspective view of aportion of the complete machine showing in detail the driving mechanismfor the hone table; Fig. 2 is a top plan view of the same; Fig. 3 is avertical section through the hone table looking in the direction of thedriving gear.

The general aim of this invention is to provide a rotatably mounted honetable driven by a friction wheel which is springpressed and normallyengages the periphery of a driving wheel, as is common in frictiondrives, the distinction over other frictional drives, being that onefriction member, namely, the idler, engaging the driving wheelfrictionally engages the second friction member or driven element,herein the hone table, and the latter has no direct connectionwhatsoever with the driving wheel. The friction wheel which engages thedriv- Specification of Letters Patent.

periphery thereof with Patented J an. 11, 1916. Serial No. 879,166.

' described and claimed as applied to a grinding machine.

Referring to the drawings, particularly Fig. 1, it will be seen that thedriving wheel 1s a groove pulley I mounted upon shaft 2 rotated by meansof a cord belt 3 the tension of which may be varied by any suitablemeans, as by the belt tightener 4. This cord belt 3 may be driven in anymanner as by an electric motor for convenience, although any means formoving the belt may be employed, or in fact any means may be employedfor rotating the shaft 2. The standards 5 which carry bearings for theshaft 2 have extending therefrom a bracket 6 which has a boss or tubularbearing 7'rising from it. Around this boss is mounted a collar 8carrying a swinging arm 9 upon the end of which is rotatably mounted afriction wheel 10. This friction wheel or idler stands in an uprightplane at right angles to the driving wheel and is positioned so as tonormally engage at or near the a light contact just suflicient to drivethe idler 10 without producing undue strain upon the motor or othermeans used for driving the shaft 2. Mountedon the bracket 6, is a guiderod 11 horizontally disposed and carrying a spring 12 which engages aprojection 13 secured to the arm 9 forthe purpose of swinging it andholding the idler. resiliently against the driver. Thebearing 7 isprovided with a bore 14 which receives the upright stub shaft'15 of thedriven element, herein a hone table 16, the periphery of which isflanged to receive a hone block or stone 17. The present invention isnot concerned with the hone stone, nor with any substitute therefor, butaims to provide generally an abrasive means for honing razor blades. Thehone 10 as-seen in Fig.3.

, stated, the friction table 16 rests near its periphery on andfrictionally engages the friction wheel or idler In the'operation of thedevice referring to Fig. 2, it will be seen that normally the spring 12is so adjusted as to hold the fries tion idler in light contact with theperiphery of the driving wheel 15 so thatthe various rotating parts aremoving in the direction indicatedby arrows. Under normal runningconditions where there would be no attempt to hone the blades thefriction between the table 16 and friction idler 10 would be that duesimply to the weight of the table and the stone; and, as before betweendriving wheel 1 and idler 10 would be a minimum due to spring 12. Whenpressure is brought to bear upon the stone 17 the pressure will serve toretard the motion of the hone table 16 so that the latter "will not movequite as rapidly as it had moved previously, although the friction idler10 which is contacting with the table 16, is still rotating at itsnormal or initial speed under the action of the drive wheel 1. tocausethe frictionwheel 10- to move or creep through aslight are under theperiph- 'ery of the hone table 16 in the direction indicated by thelnclosed arrow, as permitted by its swinging support,,so that closercontactis madebetween the friction idler 10,

and the drive wheel, thereupon immediately drawing additional power fromthe sourcedriving'the shaft 2. It will be readily understood that 1f thepressure upon the hone table remains constant for a time, the pressurebetween the drive wheel and'the friction idler will remain the same aswas the case when pressure was first applied to' the hone table, but ifany additional pressure be brought to bear upon the hone table 16,

a still closer. contact will the driver and the idler. Upon release ofthe pressure on the hone stone 17 the spring .12 again acts alone tohold the idler or friction wheel 10 to normal position. Hence be madebetween the feed of the driving power is automatic,

although it is necessary for the attendant who'is using the machine toexercise constant care and effort to grind the razor blades. 1

What I claim is 1. A changeable driving mechanism com-V.

prising a driven element, adriving element, an idler normally in lightengagement with both, and a movable support'for said idler .whereby itsengagement with the driver is altered when a load is thrown onto thedriven element. I

2. A changeable driving mechanism comprising a rotary driven element, arotary driving element, an idler wheel normally in light frictionalengagement with-both,

The effect of this condition will be r increased when a load is thrownonto, the

an arm having a collar and a movable support for said idler wheelwhereby its frictional contact-with saiddriver is lncreased when a loadis thrown onto the driven element.

4:. A frictional driving mechanism comprising a rotary driver, a drivenelement,

an idler wheel in constant engagement with said element, meansforvforcing it normally into light frictional engagement with thedriver, and a movable support for said wheel whereby its frictionalcontact with said driver is increased when a load is thrown.

onto the driven element.

5. A frictional driving mechanism comprising a rotary driver, an idlerwheel,

means for forcing it normally into light frictional engagement with thedriver, a driven element resting on the idler wheel, anda movablesupport for said wheel whereits frictional contact with said driver isdriven element. 7 e V I 6. A varlable friction. drive comprising drivmgand driven wheels, a frictlonidler contacting with both, aswingingsupport forthe idler movable with respectto the driven wheel,and means for-swinging the support to hold the idler normally in lightcontact with said driver.

7 A variable friction driving and driven wheels, a friction idler wheeluponwhich the driven wheel rests, .a swinging support for the idlermounted c.0- axially with the driven wheel, anda'spring for swinging thesupport to hold the idler normally in light contact with said driver.

drive comprising 8. In a variable friction driving mecha- I nism forgrind stones and the like, the combinationwith a rotary table mounted ona V vertlcal axis; of a driving wheel rotating in a plane at rightangles to that of the table, pivotallymounted around the axis of saidtable and beneath the'latter, an idler wheel journaled on the arm and inconstant contact with the-under side of the table, a guide rod directedtoward the driver, and a spring on the rod swinging said arm on itssupport to throw the idler normally into light contactnn'th the driver,a

for the purpose set forth. 7 V

9. In a variable friction driving mechanism for grind stones and thelike; the combination with'a rotary table-mounted on a vertical axis; ofa driving wheel rotatingin a plane at angles to that of the table, anarm pivotally mounted around the axis of said table and beneath thelatter, an idler wheel throw the idler into light contact with the 10journaled on the arm and in constant conside of said driver, for thepurpose set forth. tact with the under side of the table, a In testimonywhereof I aflix my signature framework having a bearing for the shaft inpresence of two witnesses.

of the table, a guide rod mounted in said framework, a projection on thearm oppo- ALBERT HILL site said rod, and an expansive spring sur-Witnesses:

rounding. the rod and engaging the projec- CARRIE M. THOMSON,

tion and normally swinging the arm to LOIS THOMPSON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

